SELECT id, ort, fachwort, (
6368 * SQRT(2*(1-cos(RADIANS(lng)) *
cos(0.20373812631684) * (sin(RADIANS(lat)) *
sin(0.83378929060067) + cos(RADIANS(lat)) *
cos(0.83378929060067)) - sin(RADIANS(lng)) * sin(0.20373812631684)))) AS entfernung
FROM literatur WHERE
6368 * SQRT(2*(1-cos(RADIANS(lng)) *
cos(0.20373812631684) * (sin(RADIANS(lat)) *
sin(0.83378929060067) + cos(RADIANS(lat)) *
cos(0.83378929060067)) - sin(RADIANS(lng)) * sin(0.20373812631684))) <= 25
ORDER BY entfernung